The present invention relates generally to the field of telecommunications and, in particular, to increased transmission capacity for a fiber-optic link.
Telecommunications systems transmit data, e.g., voice video and other data, between equipment at various locations. This equipment includes user equipment, access equipment, switches, and other conventional telecommunications equipment. Telecommunications systems typically include a variety of transmission medium to transmit data to and from the equipment. For example, some systems transmit data over one or more of coaxial cables, fiber optic cables, or other appropriate medium.
Over time, service providers increase the capacity of their systems to keep up with an ever-increasing demand for access to the system. One typical technique for increasing the capacity of the system is to increase the speed at which data is transmitted over the system. Unfortunately, when fiber-optic cables are used to transmit data, other aspects of the transmission medium limit the effectiveness of the increased speed. For example, the xe2x80x9cdispersionxe2x80x9d effect limits the ability of the service provider to increase the speed of data carried over the fiber-optic cable. The dispersion effect occurs when the light transmitted over the cable broadens out to the point where the information carried by the light is corrupted. To compensate for this effect, conventionally, expensive dispersion compensation circuitry is included in the system. However, in some applications, the expense of this additional circuitry outweighs the benefits of the increased speed of transmission.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for increased capacity in transmission systems without the use of expensive dispersion compensation circuitry.
The above mentioned problems with telecommunications and other problems are addressed by embodiments of the present invention and will be understood by reading and studying the following specification. Embodiments of the present invention encode multiple digital data streams into a composite signal using, for example, pulse amplitude modulation and transmitting the composite signal over a fiber-optic link in order to improve the capacity of the link.
More particularly, in one embodiment, an optical communication system is provided. The optical communication system includes an optical fiber, an optical transmitter, and an optical receiver. The optical transmitter is coupled to the optical fiber. The optical transmitter is adapted to encode an optical signal based on at least two, independent input signals. The optical receiver is coupled to the optical fiber. The optical receiver is adapted to decode the optical signal to reproduce the at least two, independent input signals as output signals.